darwin, x86, testsuite - Amend popcnt match string for Darwin.

Darwin uses a different spelling for popcnt (popcnt instead of popcntw).
Check for this in the test.

2019-05-25  Iain Sandoe  <iain@sandoe.co.uk>

	* gcc.target/i386/pr59874-3.c: Use the spelling of popcnt
	expected for Darwin.

From-SVN: r271623

gcc/testsuite/ChangeLog

+2019-05-25  Iain Sandoe  <iain@sandoe.co.uk>
+
+	* gcc.target/i386/pr59874-3.c: Use the spelling of popcnt
+	expected for Darwin.
+
 2019-05-25  Iain Sandoe  <iain@sandoe.co.uk>
 
 	* gcc.target/i386/pr89261.c: Test that the alignment required

gcc/testsuite/gcc.target/i386/pr59874-3.c

 /* PR target/59874 */
 /* { dg-do compile } */
 /* { dg-options "-O2 -mpopcnt -masm=att" } */
-/* { dg-final { scan-assembler "popcntw" } } */
+/* { dg-final { scan-assembler "\tpopcntw" { target { ! *-*-darwin* } } } } */
+/* { dg-final { scan-assembler "\tpopcnt" { target *-*-darwin* } } } */
 
 unsigned int
 foo (unsigned short x)